Skip to main content

In-situ synthesis and sintering of mullite glass composites by SPS


The main subject of this work is an investigation of the effects of heating rate and current on the crystallisation of amorphous precursors in spark plasma sintering (SPS). For this, dry gel of Al2O3-SiO2 with a molar ratio of 1:1, was synthesized and sintered in-situ by SPS, and also by hot pressing (HP) for comparison. Phase analysis showed that the only crystalline product in both cases was mullite, whose Al2O3 content was lower in the SPS specimens. The microstructures showed a low volume fraction of large mullite fibers in the SPS specimens, whereas a high volume fraction of fine equiaxed grains was present in the HP specimen. The main difference in microstructure between HP and SPS specimens could be explained in terms of the higher heating rate of the SPS specimens. The size of the SPS die also affected the size and aspect ratio of the mullite fibers produced, which might have been due to either the different electrical current required or a difference in specimen temperature profile.


  1. Roy JF, Descemond M, Brodhag C, et al. Alumina microstructural behaviour under pressureless sintering and hot-pressing. J Eur Ceram Soc 1993, 11: 325–333.

    Article  Google Scholar 

  2. Conrad H, Yang D. Dependence of the sintering rate and related grain size of yttria-stabilized polycrystalline zirconia (3Y-TZP) on the strength of an applied DC electric field. Mat Sci Eng A 2011, 528: 8523–8529.

    Article  Google Scholar 

  3. Olevsky EA, Kandukuri S, Froyen L. Consolidation enhancement in spark-plasma sintering: Impact of high heating rates. J Appl Phys 2007, 102: 114913.

    Article  Google Scholar 

  4. Holland TB, Tran TB, Quach DV, et al. Athermal and thermal mechanisms of sintering at high heating rates in the presence and absence of an externally applied field. J Eur Ceram Soc 2012, 32: 3675–3683.

    Article  Google Scholar 

  5. Gendre M, Maître A, Trolliard G. A study of the densification mechanisms during spark plasma sintering of zirconium (oxy-)carbide powders. Acta Mater 2010, 58: 2598–2609.

    Article  Google Scholar 

  6. Galy J, Dolle M, Hungria T, et al. A new way to make solid state chemistry: Spark plasma synthesis of copper or silver vanadium oxide bronzes. Solid State Sci 2008, 10: 976–981.

    Article  Google Scholar 

  7. Wang K-Y. Non-equilibrium chemical reactions with rapid heating and quenching. Energy 1987, 12: 291–302.

    Article  Google Scholar 

  8. Chen S, Wang W, Kono H, et al. Abnormal grain growth of hydroxyapatite ceramic sintered in a high magnetic field. J Cryst Growth 2010, 312: 323–326.

    Article  Google Scholar 

  9. Yang D, Conrad H. Influence of an electric field on grain growth in extruded NaCl. Scripta Mater 1998, 38: 1443–1448.

    Article  Google Scholar 

  10. Conrad H, Guo Z, Sprecher AF. Effect of an electric field on the recovery and recrystallization of Al and Cu. Scripta Metall 1989, 23: 821–823.

    Article  Google Scholar 

  11. Fischer RX, Schneider H. The mullite-type family of crystal structures. In Mullite. Schneider H, Komarneni S, Eds. John Wiley & Sons, 2006: 93–128.

    Google Scholar 

  12. Cameron WE. Mullite: A substituted alumina. Am Mineral 1977, 62: 747–755.

    Google Scholar 

  13. Schneider H, Fischer RX, Voll D. Mullite with lattice contents a > b. J Am Ceram Soc 1993, 76: 1879–1881.

    Article  Google Scholar 

  14. Anselmi-Tamburini U, Gennari S, Garay JE, et al. Fundamental investigations on the spark plasma sintering/synthesis process: II. Modeling of current and temperature distributions. Mat Sci Eng A 2005, 394: 139–148.

    Article  Google Scholar 

  15. Ghate BB, Hasselmann DPH, Spriggs RM. Kinetics of pressure-sintering and grain-growth of ultra-fine mullite powder. Ceram Int 1975, 1: 105–110.

    Article  Google Scholar 

  16. Huang TH, Rahaman MN, Mah T-I, et al. Anisotropic grain growth and microstructural evolution of dense mullite above 1550 °C. J Am Ceram Soc 2000, 83: 204–210.

    Article  Google Scholar 

  17. Lee J-E, Kim J-W, Jung Y-G, et al. Effects of precursor pH and sintering temperature on synthesizing and morphology of sol-gel processed mullite. Ceram Int 2002, 28: 935–940.

    Article  Google Scholar 

  18. Arora A, Marshall DB, Lawn BR. Indentation deformation/fracture of normal and anomalous glasses. J Non-Cryst Solids 1979, 31: 415–428.

    Article  Google Scholar 

  19. Bertoldi M, Sglavo VM. Soda-borosilicate glass: Normal or anomalous behavior under Vickers indentation? J Non-Cryst Solids 2004, 344: 51–59.

    Article  Google Scholar 

  20. Mukhopadhyay A, Chu BTT, Green MLH, et al. Understanding the mechanical reinforcement of uniformly dispersed multiwalled carbon nanotubes in alumino-borosilicate glass ceramic. Acta Mater 2010, 58: 2685–2697.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Jinyong Zhang.

Additional information

This article is published with open access at

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Zhang, J., Zhan, H., Fu, Z. et al. In-situ synthesis and sintering of mullite glass composites by SPS. J Adv Ceram 3, 165–170 (2014).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • spark plasma sintering (SPS)
  • synthesis
  • extra-field
  • mullite